There are several practical problems which are encountered in the lyophilization, storage and reconstitution of fluid products, particularly blood. One of the objects, particularly in dealing with blood or other medical products, is to handle the blood as little as possible to minimize exposure to sources of possible contamination. Furthermore, the blood should be able to be conveniently stored in its lyophilized state in a sterile environment and then reconstituted with as little handling as possible and with minimal exposure to possible sources of contamination.
There is the practical problem of conservation of storage space. It would be desirable to have the container in which the blood is stored take up the minimum amount of room, since in many instances, it is stored in a controlled temperature environment, such as a refrigerator, in which space is limited.
Another problem is that the container for the blood must not only be susceptible to sterilization, but must also mechanically withstand low temperatures, particularly, for example, liquid nitrogen temperatures, used for lyophilization processes, and withstand application of a vacuum.
To minimize storage utilization, the above requirements suggest the use of a flexible, collapsible container. On the other hand, if the contents of the bag are to be lyophilized under vacuum, the bag must be able to withstand application of a vacuum without collapsing during lyophilization.
It is thus an object of the present invention to provide a lyophilization bag which can be used during lyophilization, then collapsed to conserve space during storage, which is versatile enough to allow one to reconstitute the contents within the bag so that they may be used directly from the bag, which will provide a fully-enclosed sterile container system. Thus, according to the invention, the same container may be used for lyophilization, storage and reconstitution, thus avoiding transfers of the contents for these purposes.
This and other objects of the invention will be apparent from the following description and accompanying drawings and appended claims.